Chemical mechanical planarization composition for polishing oxide materials and method of use thereof

ABSTRACT

Polishing compositions comprising ceria coated silica particles and organic acids having one selected from the group consisting of sulfonic acid group, phosphonic acid group, pyridine compound, and combinations thereof, with pH between 5 and 10 and electrical conductivity between 0.2 and 10 millisiemens per centimeter provide very high silicon oxide removal rates for advanced semiconductor device manufacturing.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional PatentApplication No. 62/716,784 and U.S. Provisional Patent Application No.62/716,769, both filed on Aug. 9, 2018, which are incorporated herein byreference as if fully set forth.

BACKGROUND

This application relates to chemical mechanical planarization/polishing(“CMP”) compositions (CMP slurries, CMP compositions or CMP formulationsare used interchangeably) used in the production of semiconductordevices, and polishing methods for carrying out chemical mechanicalplanarization. In particular, it relates to polishing compositionscomprising composite abrasive particles that are suitable for polishingpatterned semiconductor wafers composed of oxide materials.

Silicon oxide (silica) is widely used as a dielectric material in thesemiconductor industry. There are several CMP steps in the integratedcircuit (IC) manufacturing process, such as shallow trench isolation(STI), inter-layer dielectric (ILD) CMP and gate poly CMP, for example.Typical oxide CMP slurry comprises an abrasive, with or without otherchemicals. The other chemicals include dispersants to improve slurrystability, boosters to increase removal rate, and inhibitors to decreaseremoval rate and to stop polishing when a stopper layer is reached, forexample, SiN in STI applications.

Common abrasives used in CMP slurries include, but are not limited to,silica, alumina, zirconia, titania and ceria. Ceria is well-known forits high reactivity toward silica. Ceria is widely used in STI CMPslurry to provide the greatest oxide removal rate (RR) due to is highreactivity to silica.

Cook et al. (Lee M. Cook, Journal of Non-Crystalline Solids 120 (1990)152-171) proposed a ‘chemical tooth’ mechanism to explain thisextraordinary property of ceria. According to this mechanism, when ceriaparticles are pressed onto silicon oxide film, ceria breaks down silicabonds, forms a Ce—O—Si structure, and thus cleaves silica from thesurface.

As semiconductor technology has evolved, there are new applications thatdemand innovative CMP solutions to provide high silicon oxide removalrates and a high degree of planarity. One such application ismanufacturing three-dimensional (3D) memory structures. 3D memorystructures stack the memory cells vertically, allowing a wider gapbetween each cell, to overcome patterning restrictions. For example, 3DNAND memory structures typically use alternating layers of thick oxidesand nitride, or oxide and conductor layers, to form vertical NANDstructures in the form of a staircase. In these applications, oxidelayers are typically thicker than 3 microns. In order to maintainthroughput requirements, oxide layers must be polished at very highrates, as disclosed in US2017133236.

Therefore, there are significant needs for CMP compositions, methods,and systems that can provide high removal rates of silicon oxide, highplanarization efficiency and excellent slurry stability.

BRIEF SUMMARY

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

Disclosed embodiments, as described below and as defined by the claimswhich follow, comprise CMP polishing compositions for polishing oxidematerial, and related methods and systems, that satisfy the need forpolishing semiconductor wafers comprising silicon oxide structures atvery high removal rates.

The disclosed embodiments satisfy the need in the art by providingcompositions, methods and systems that allow high removal rates ofsilicon oxide when polishing semiconductor wafers, high planarizationefficiency and excellent slurry stability. For example, an embodimentsatisfies the need for polishing semiconductors at silicon oxide removalrates of greater than 10000 Angstroms/minute. Preferred embodimentssatisfy the need for polishing semiconductors at silicon oxide removalrates of greater than 12500 Angstroms/minute, or greater than 15000Angstroms/minute, during polishing at 4 psi downforce and 126 RPM tablespeed with 150 ml/min slurry flow rate on a 300 mm wafer polisher.Formulations disclosed in this application are especially useful forpolishing semiconductor wafers for 3D-NAND memory structureapplications.

Embodiments of the CMP slurry formulations described herein compriseabrasive particles, a silicon oxide removal rate accelerator and asolvent. The CMP slurry formulations may optionally comprise additivesfor pH and conductivity adjustment, biological growth inhibition,surfactants, dispersants, and functional additives such as chemicals forsuppression of stopper films.

Preferred abrasives include, but are not limited to, composite ceriaabrasives formulated with a SiO₂ (silica) core that is covered with fineceria abrasive particles forming a shell. Preferred silicon oxideremoval rate accelerators include, but are not limited to, salts, suchas salts of nitrate, phosphate, phosphonates, sulphate, sulphonates,carboxylate or combinations thereof, corresponding acids such as nitric,sulfonic, sulfuric, phosphonic, phosphinic, carboxylic or combinationsthereof. Preferably the slurry formulation has a pH of 7 to 11 which ispreferably adjusted using a suitable acid or base including, but notlimited to, HNO3 and NH4OH. Preferably, the slurry formulation has aconductivity 0.3-9 mS/cm.

In addition, several specific aspects of the systems and methods of thesubject matter disclosed herein are outlined below.

Aspect 1: A chemical mechanical planarization (CMP) composition forpolishing oxide material comprising:

an abrasive selected from the group consisting of inorganic oxideparticles, doped inorganic oxide particles, surface coated compositeinorganic oxide particles, organic polymer particles, inorganic oxidecoated organic polymer particles, and combinations thereof;

a removal rate accelerator; and

a solvent;

wherein the composition further comprises a pH greater than 5.

Aspect 2: The CMP composition of Aspect 1, wherein the abrasive isselected from the group consisting of cerium oxide (ceria), aluminumoxide, zirconium oxide, zirconium silicate, tin oxide, silicon dioxide,titanium oxide, germanium oxide, vanadium oxide, doped inorganic oxide,composite inorganic oxide and combinations thereof.

Aspect 3: The CMP composition in Aspect 2, wherein the abrasivecomprises cerium oxide selected from the group consisting of calcinedceria, colloidal ceria, ceria coated silica particles, and combinationsthereof.

Aspect 4: The CMP composition of Aspect 3, wherein the abrasivecomprises ceria coated silica particles, the ceria coated silicaparticles comprising an amorphous silica core particle coated withcrystalline ceria nanoparticles.

Aspect 5: The CMP composition of Aspect 4, wherein the crystalline ceriananoparticles comprise a single crystal.

Aspect 6: The CMP composition of Aspect 4, wherein a weight ratio of theceria nanoparticles to the amorphous silica core particle is 0.01 to 1.5or greater.

Aspect 7: The CMP composition of Aspect 4, wherein the amorphous silicacore particles comprise a diameter ranging from 20 to 550 nanometers andthe ceria nanoparticles comprise a diameter greater than 10 nanometers,wherein the diameter of the amorphous silica core particles is greaterthan the diameter of the ceria nanoparticles.

Aspect 8: The CMP composition of any of Aspects 1-7, wherein the removalrate accelerator is an organic acid or an organic acid salt having oneselected from the group consisting of a sulfonic acid group, aphosphonic acid group, a pyridine group, and combinations thereof.

Aspect 9: The CMP composition of any of Aspects 1-8, wherein the removalrate accelerator is a salt selected from the group consisting ofnitrate, phosphate and sulphate.

Aspect 10: The CMP composition in any of Aspects 1-9, wherein thesolvent is selected from the group consisting of water, a polarnon-aqueous solvent, and a mixture thereof.

Aspect 11: The CMP composition in Aspect 10, wherein the non-aqueoussolvent is selected from the group consisting of alcohol, ether, ketoneand combinations thereof.

Aspect 12: The CMP composition of any of Aspects 1-11, wherein theremoval rate accelerator is an acid selected from the group consistingof nitric, sulphonic, sulfuric, phosphonic, carboxylic and combinationsthereof.

Aspect 13: The CMP composition of any of Aspects 1-12 wherein theremoval rate accelerator is an acid selected from the group consistingof phenyl phosphonic acid, benzoic acid, acetic acid, malonic acidglutaric acid, oxalic acid and combinations thereof.

Aspect 14: The CMP composition of any of Aspects 1-13, wherein theremoval rate accelerator is a sulfonic acid selected from the groupconsisting of methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, p-toluene sulfonic acid, ethane di sulfonic acid,naphthalene di sulfonic acid, acrylamido propane sulfonic acid,morpholinopropanesulfonic acid, 3-(N-Morpholino)propanesulfonic acid(MOPS), 4-Morpholineethanesulfonic acid (MES),beta-Hydroxy-4-morpholinepropanesulfonic acid (MOPSO),4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES),1,4-piperazinediethanesulfonic acid (PIPES),piperazine-1,4-bis(2-hydroxypropanesulfonic acid)dihydrate (POPSO),4-(2-Hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS),piperazinediethane sulfonic acid, hydroxyethylpiperazine ethane sulfonicacid, and combinations thereof.

Aspect 15: The CMP composition in Aspect 8, wherein the removal rateaccelerator is an organic acid having a pyridine group having astructure of:

wherein R1, R2, R3, R4 and R5 are independently selected from the groupconsisting of hydrogen, a carboxylic acid, a carboxylic acid ester, anorganic sulfonic acid, an organic amine, an organic amide and a hydroxylgroup.

Aspect 16: The CMP composition in Aspect 15, wherein at least one of R1,R2, R3, R4 and R5 is a carboxylic acid.

Aspect 17: The CMP composition of any of Aspects 1-16, wherein theremoval rate accelerator is a pyridine compound selected from the groupconsisting of: pyridine; pyridine monocarboxylic acid; pyridinedicarboxylic acid; picolinic acid; nicotinic acid; isonicotinic acid;dipicolinic acid; 2,5-pyridinedicarboxylic acid;3,5-pyridinedicarboxylic acid; 2,3-pyridinedicarboxylic acid; and3,4-pyridinedicarboxylic acid.

Aspect 18: The CMP composition of any of Aspects 1-17, wherein a pH ofthe CMP composition ranges from 7 to 11.

Aspect 19: The CMP composition of any of Aspects 1-18, wherein aconductivity of the CMP composition ranges from 0.3 to 9 millisiemensper centimeter.

Aspect 20: The CMP composition of any of Aspects 1-19, wherein thecomposition comprises at least one additive selected from the groupsconsisting of an additive for removal rate selectivity, a pH adjuster, asurfactant, a dispersant, and a biological growth inhibitor.

Aspect 21: The CMP composition in any of Aspects 1-20, wherein theabrasive comprises particles having a zeta potential more negative than−25 millivolts.

Aspect 22: A polishing method for chemical mechanical planarization(CMP) of a semiconductor device comprising a first material and a secondmaterial, comprising the steps of:

(a) contacting at least one surface of the first material with a CMPpolishing pad;

(b) delivering the CMP polishing composition in any of Aspects 1-21 tothe at least one surface;

(c) polishing the at least one surface with the polishing composition toremove the first material at a removal rate of greater than 10000Angstroms/minute.

Aspect 23: The polishing method of Aspect 22, wherein the first materialis a silicon oxide material selected from the group consisting ofthermal oxide, TEOS films deposited using Tetra Ethyl Ortho Silicate(TEOS) precursors, High Density Plasma (HDP) oxide, High Aspect RatioProcess (HARP) films, fluorinated oxide films, doped oxide films,Spin-On Glass (SOG), flowable Chemical Vapor Deposited (CVD) films,optical glass, display glass, and combinations thereof.

Aspect 24: The polishing method of Aspect 23, wherein the secondmaterial is selected from the group of silicon nitride, polysilicon, andcombinations thereof.

Aspect 25: A system for chemical mechanical planarization, comprising:

(a) a patterned substrate comprising at least one surface having a firstmaterial and a second material;

(b) a polishing pad; and

(c) the CMP polishing composition in any of Aspects 1-21;

wherein the at least one surface is in contact with the polishing padand the polishing composition and the first material is a silicon oxidematerial selected from the group consisting of thermal oxide, TEOS filmsdeposited using Tetra Ethyl Ortho Silicate (TEOS) precursors, HighDensity Plasma (HDP) oxide, High Aspect Ratio Process (HARP) films,fluorinated oxide films, doped oxide films, Spin-On Glass (SOG),flowable Chemical Vapor Deposited (CVD) films, optical glass, displayglass, and combinations thereof.

DETAILED DESCRIPTION

The ensuing detailed description provides preferred exemplaryembodiments only, and is not intended to limit the scope, applicability,or configuration of the claimed invention. Rather, the ensuing detaileddescription of the preferred exemplary embodiments will provide thoseskilled in the art with an enabling description for implementing thepreferred exemplary embodiments. Various changes may be made in thefunction and arrangement of elements without departing from the spiritand scope of the invention, as set forth in the appended claims.

All terms defined herein should be afforded their broadest possibleinterpretation, including any implied meanings as dictated by a readingof the specification as well as any words that a person having skill inthe art and/or a dictionary, treatise, or similar authority would assignparticular meaning. Further, it should be noted that, as recited in thespecification and in the claims appended hereto, the singular forms “a,”“an,” and “the” include the plural referents unless otherwise stated.Additionally, the terms “comprises” and “comprising” when used hereinspecify that certain features are present in that embodiment, but shouldnot be interpreted to preclude the presence or addition of additionalfeatures, components, operations, and/or groups thereof.

Disclosed herein are CMP polishing compositions for polishing oxidematerial, and related methods and systems, that satisfy the need forpolishing semiconductor wafers comprising silicon oxide structures atvery high removal rates.

The CMP slurry formulations described herein comprise an abrasive, alsoreferred to herein as abrasive particles, one or more additives thataccelerate the removal rate of silicon oxide films and a solvent. TheCMP slurry formulations may optionally comprise additives for pHadjustment, conductivity adjustment, biological growth inhibition,surfactants, dispersants, and functional additives such as chemicals forsuppression of stopper films.

The paragraph headings that follow are solely to provide organization tothe disclosure and are not intended to limit the scope of the claimedinvention in any way.

Abrasive

The abrasive, also referred to herein as abrasive particles, maycomprise one or more metal oxide, one or more metalloid oxide or achemical mixture of metal oxides and metalloid oxides. Preferredabrasives include, but are not limited to, inorganic oxide particles,doped inorganic oxide particles, composite inorganic oxide particles,organic polymer particles, inorganic oxide coated organic polymerparticles, or combinations thereof.

Abrasive particles may have different chemical and physical formsincluding, but not limited to, chemically homogeneous, doped, surfacemodified, and core-shell with continuous or discontinuous shell layers.

As used herein, “doped” inorganic oxide particles refers to abrasiveparticles in which secondary inorganic metal ions (in metal oxide form)are intentionally introduced into a structure of the primary metal ions.For example, ceria may be doped with lanthanum or another secondarymetal ion. The secondary metal ion is introduced and uniformlydistributed in the original material structure (a lattice if it iscrystal). Doped abrasives maintain a single phase before and afterdoping.

As used herein, “composite” inorganic oxide particles refer to two metaloxides connected to each other either physically or chemically to form asingle particle. Examples of composite particles include, but are notlimited to, core-shell particles and surface-coated particles. Incontrast to doped metal oxides, composite inorganic oxide particlesconsist of more than one phase.

Preferred metal oxide abrasives include, but are not limited to,alumina, ceria, germania, silica, spinel, titania, an oxide or nitrideof tungsten, zirconia, or any of the above doped with one or more otherminerals or elements, and any combination thereof. The metal oxideabrasive may be produced by any of a variety of techniques, includingsol-gel, hydrothermal, hydrolytic, plasma, pyrogenic, aerogel, fumingand precipitation techniques, and any combination thereof.

Precipitated metal oxides and metalloid oxides can be obtained by knownprocesses by reaction of metal salts and acids or other precipitatingagents.

Pyrogenic metal oxide and/or metalloid oxide particles are obtained byhydrolysis of a suitable, vaporizable starting material in anoxygen/hydrogen flame. An example is pyrogenic silicon dioxide fromsilicon tetrachloride. The pyrogenic oxides of aluminum oxide, titaniumoxide, zirconium oxide, zirconium silicate, silicon dioxide, ceriumoxide, tin oxide, germanium oxide, vanadium oxide, and chemical andphysical mixtures thereof are preferred abrasives.

A more preferred abrasive particle comprises cerium oxide (ceria).Examples of abrasive particles comprising cerium oxide include, but arenot limited to, calcined ceria, colloidal ceria and ceria coated silicaparticles. A most preferred abrasive is a composite inorganic oxidecomposed of ceria coated silica particles.

Ceria coated silica particles comprise amorphous silica particles ascore particles and ceria as nanoparticles covering the core as a shell.The surface of each silica particle is covered by ceria nanoparticles.The silica core particles are amorphous, and the ceria nanoparticles arecrystalline or more preferably single crystalline. As used herein,single crystalline refers to a continuous crystalline structure.

The quantity of nanoparticles covering the surface of the core particlespreferably falls within the following range in terms of the solid weightratio. The solid weight (b) of the nanoparticles relative to the solidweight (a) of the core particles is (b)/(a)=0.01 to 1.5, more preferably0.01 to 1.2.

The diameter of the ceria nanoparticles covering the core particle ispreferably greater than 10 nanometers, more preferably greater than 13nanometers. The core particle diameter may range from 15 to 500nanometers, preferably from 20 to 250 nanometers, most preferably from50 to 200 nanometers. Preferably, the core particle diameter is greaterthan diameter of the shell particles. As used herein, the term diameterrefers to an absolute diameter of the particles.

In preferred embodiments, the ceria coated silica particles do notdisintegrate under polishing forces. Particles that do not break downunder the action of polishing forces (i.e. disintegrative forces) andkeep the characteristic of original particle size maintain a highremoval rate during polishing. If the particles disintegrate underpolishing forces, the removal rate will decrease due to an effectivelysmaller abrasive particle size. Breaking of the particles may also yieldirregular shaped particles which may produce the undesirable effect ofscratching defects.

Particle stability under disintegrative forces can be determined bysubjecting the formulation to ultrasonication treatment for half an hourand measuring the changes in size distribution. Preferred conditions forultrasonication treatment are a half-hour immersion in a bath with 42kilohertz frequency at 100 watt output.

Particle size distribution can be measured by using any suitabletechnique such as Disc Centrifuge (DC) method or Dynamic LightScattering (DLS). Changes in size distribution can be characterized interms of changes in mean particle size or D50 (50 percent particlesbelow this size) or D99 (99 percent particles below this size) or anysimilar parameters. Preferably the changes in particle size distributionof ceria coated silica particles after ultrasonication treatment is lessthan 10 percent, more preferably less than 5 percent or most preferablyless than 2 percent; by using for example DC and mean particle size,D50, D75 and/or D99.

Using such stable particles in CMP slurry formulations allows moreeffective utilization of polishing forces for film material removal andwould also prevent generation of any irregular shapes that wouldcontribute to scratching defects.

In some embodiments, the ceria coated silica particle may also have athin layer of silicon oxide covering the cerium oxide particles. Withoutbeing bound by any particular theory, it is believed that the siliconoxide covering helps stabilize the particle and makes the surface of theparticle more negatively charged.

Ceria coated silica particles may be manufactured by any suitablemethod. Examples of suitable methods of manufacturing are described infollowing patents which are incorporated herein in their entirety:JP6358899, JP6285775, JP2016084243, US2018105428, JP2017043531,JP2017193692, JP2017206410, JP2017206411, WO18088088, WO18121508,JP2016127139, U.S. Pat. Nos. 9,447,306, 6,645,265, JP5979340,WO2005/035688, US2012/077419, US2003/118824.

Silicon Oxide Removal Rate Accelerators

The CMP slurry formulation may comprise one or more compounds foraccelerating the silicon oxide removal rate, referred to herein assilicon oxide removal rate accelerators. Preferred silicon oxide removalrate accelerators are: organic acids having at least one of a sulfonicacid group or a phosphonic acid group, organic acids comprising pyridinefunctionality, and combinations thereof.

The silicon oxide rate accelerators comprising organic acids having asulfonic acid group (also referred to herein as sulfonic acids) includebut are not limited to aromatic sulfonic acids, aliphatic sulfonicacids, piperazine sulfonic acids, disulfonic acids, aromatic andaliphatic sulfonic acids with amino groups, salts thereof, andcombinations thereof. The organic acids having sulfonic acid groups donot include compounds containing a nitrogen atom bonded with hydrogenatoms. The silicon oxide removal rate accelerators comprising sulfonicacid do not include any polymeric or surfactant compounds containingsulfonic acid groups.

Preferred organic acids having a sulfonic acid group include, but arenot limited to, methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, p-toluene sulfonic acid, ethane disulfonic acid,naphthalene disulfonic acid, acrylamido propane sulfonic acid,morpholinopropanesulfonic acid, 3-(N-Morpholino)propanesulfonic acid(MOPS), 4-Morpholinoethanesulfonic acid (MES),beta-Hydroxy-4-morpholinepropanesulfonic acid (MOPSO),4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES),1,4-piperazinediethanesulfonic acid (PIPES),piperazine-1,4-bis(2-hydroxypropanesulfonic acid)dihydrate (POPSO),4-(2-Hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS),piperazinediethane sulfonic acid, and hydroxyethylpiperazine ethanesulfonic acid.

More preferably, the organic acid having a sulfonic acid group isselected from the group consisting of methanesulfonic acid,benzenesulfonic acid, toluene sulfonic acid, p-toluene sulfonic acid,ethane disulfonic acid, naphthalene disulfonic acid,4-(2-Hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS),piperazinediethane sulfonic acid, hydroxyethylpiperazine ethane sulfonicacid, and combinations thereof.

In some embodiments, the silicon oxide removal rate accelerator is anorganic acid having a phosphonic acid group (also referred to herein asan organic phosphonic acid), including, but not limited to, substitutedphosphonic acids with a general formula of R—P(O)(OH)₂; where R can beany substituent moiety except hydrogen. These embodiments include thecorresponding phosphonic acid salts, combinations thereof andcombinations of acids and slats. Preferred organic phosphonic acids arephenyl phosphonic acid, linear alkyl phosphonic acids with the generalformula CH₃—(CH₂)_(n)—P(O)(OH)₂; where n ranges from 1 to 25. Morepreferred organic phosphonic acids are, phenyl phosphonic acid, phenylphosphinic acid.

In some embodiments, the silicon oxide removal rate accelerator is apyridine compound including, but is not limited to, 2-pyridinecarboxylicacid, 3-pyridinecarboxylic acid, 4-pyridinecarboxylic acid, pyridine,pyridine-2,6-dicarboxylic acid, 2,2-bipyridine.

In some embodiments, the silicon oxide removal rate acceleratorcomprises a pyridine compound substituted with one or more carboxylicacid groups having a structure of Formula (I):

wherein R1, R2, R3, R4 and R5 are independently selected from groupconsisting of hydrogen, carboxylic acid, carboxylic acid ester, organicsulfonic acid, organic amine, organic amide, hydroxyl group.

In preferred embodiments, the pyridine compound comprises at least oneof the selected R group as carboxylic acid. Preferred pyridine compoundsinclude but are not limited to: 2-pyridine carboxylic acid;3-pyridinecarboxylic acid; 4-pyridinecarboxylic acid; pyridine;pyridine-2,6-dicarboxylic acid; 2,2-bipyridine and combinations thereof.

Preferred pyridine compounds and derivatives used in the CMP polishingcompositions also include, but are not limited to pyridine, pyridinemonocarboxylic acid, or pyridine dicarboxylic acid, such as picolinicacid, nicotinic acid, isonicotinic acid, dipicolinic acid,2,5-pyridinedicarboxylic acid, 3,5-pyridinedicarboxylic acid,2,3-pyridinedicarboxylic acid, and 3,4-pyridinedicarboxylic acid.

Preferred silicon oxide removal rate accelerators include, but are notlimited to, benzene sulfonic acid, toluene sulfonic acid, acetic acid,phenyl phosphonic acid, phenyl phosphinic acid and 2-pyridinecarboxylicacid.

Preferably, the concentration of silicon oxide removal rate acceleratorranges from about 0.001 weight percent to 10 weight percent relative tothe total weight of the CMP composition. More preferably the range isfrom about 0.01 weight percent to 8 weight percent. Most preferably, therange is from about 0.1 weight percent to 5 weight percent.

Solvent

The solvent may be water, one or more polar solvents, or a combinationthereof. A preferred solvent is water.

Formulation of the CMP Slurry and Physical Characteristics

The CMP composition comprises abrasive particles, silicon oxide removalrate accelerators, and a solvent. Optionally, a pH adjusting agent isused to adjust pH of the CMP composition to the optimized pH condition.Other optional ingredients may also be present as described below.

The abrasive particles are present in an amount from 0.01 weight percentto 20 weight percent, preferably, from 1 weight percent to 10 weightpercent, more preferably, from about 3 weight percent to about 8 weightpercent, based on the total weight of the CMP composition.

Preferably, the pH of the CMP composition is greater than 5, morepreferably greater than 7. This pH range is less corrosive compared toacidic pH slurries and would lead to lower pad and conditioning diskwear. Silicon oxide removal rates are also maximized in this pH range.The pH may be adjusted using suitable pH adjusters.

In a preferred embodiment, the CMP formulation comprises a compositeceria abrasive (ceria coated silica), and a salt (nitrate, phosphate,sulphate) or combined salts or corresponding acid (nitric, sulfonic,sulfuric, phosphonic, phosphinic) or combined acids or other acid(carboxylic) with pH 7-11 (adjusted by suitable acid/base such asHNO3/NH4OH) and conductivity 0.3-9 millisiemens per centimeter.

In another preferred embodiment, the formulation is made with acomposite ceria abrasive that is ceria coated silica (0.1-6 weightpercent), and BSA/phenyl phosphonic acid/phenyl phosphinic acid (up to2.5 weight percent) with pH 7-11 (adjusted by suitable acid/base such asHNO3/NH4OH) and conductivity 0.3-6 millisiemens per centimeter.

Preferably, the electrical conductivity of the slurry measured at 25degrees Celsius is between 0.1 to 20 millisiemens per centimeter, morepreferably between 0.5 and 10 millisiemens per centimeter and mostpreferably between 1 and 5 millisiemens per centimeter. The conductivitymay be adjusted by using a conductivity adjusting additive.

In order to provide a stable slurry, the abrasive particles must havesufficiently negative or positive zeta potential at the point of use andin the concentrated polishing compositions. Zeta potential may bemeasured by any suitable techniques including or not limited tostreaming potential/current measurements, electrophoretic velocitymeasurement, and electroacoustic techniques.

Zeta potential of the abrasive particles in the slurry is preferablymore negative than −25 millivolts or more positive than +25 millivolts,more preferably more negative than −30 millivolts or more positive than+30 millivolts and most preferably more negative than −35 millivolts ormore positive than +35 millivolts, as measured using electroacousticzeta potential measurement techniques.

Without being beholden to any particular theory, it is hypothesized thatthe sulfonic acid (or phosphonic acid or phosphinic acid) is able toreduce oxides in ceria to make more Ce(III) available to increase thepolishing rates of silicon oxide.

Higher oxide removal rates and highly selective oxide to nitride removalhave been achieved by slurries using calcined CeO2 abrasive in an acidicpH range from 3.5 to 5.5. Using such slurries, it has been demonstratedthat higher oxide removal rates are accompanied by higher Ce3+ activesites formed on the CeO2 abrasives. In terms of charge interaction, CeO2abrasives would be charged positively (Isoelectric Point (IEP)approximately 6 to 7) and oxide substrate charged negatively (IEPapproximately 2 to 3) in the acidic slurry (pH 4-6). A lower oxideremoval rate would be expected during polishing in an alkaline pH from 8to 10, not only due to repulsive charge interaction between the calcinedCeO2 particles and the oxide substrate, but the Ce3+ active sites on theCeO2 abrasive are “neutralized” by hydroxide ions.

In some embodiments, composite ceria abrasives are formulated with aSiO2 core which is covered with fine Ce abrasives as the shell. Theterms “composite ceria abrasive” and “ceria coated silica” are usedinterchangeably in the disclosure and claims to refer to this embodimentThe surface charge on this composite abrasive is highly negativelycharged in an environment with a pH from 2 to 10, so there would be arepulsive coulomb's force between the composite ceria abrasive and theoxide substrate, resulting in lower oxide removal rates. By introducinga salt or acid into the slurry, thereby increasing the slurry'sconductivity, the negative charge on both abrasive and oxide substrateis effectively neutralized, boosting oxide removal rates.

Advanced CMP applications require extremely low levels of metals such assodium on the dielectric surface after polishing. Therefore, it isdesired to have very low trace metals, especially sodium, in the slurryformulations. In embodiments, the formulations comprising ceria coatedsilica particles that have less than 5 ppm, more preferably less than 1ppm, most preferably less than 0.5 ppm of sodium impurity levels foreach percent of abrasive particles in the formulations by weight.

Optional Functional Additives

CMP slurry formulations may comprise optional functional additives toperform various functions including, but not limited to, modifyingremoval rate selectivity between silicon oxide films and some otherfilms such as silicon nitride or polysilicon, boosting removal rates,adjusting within wafer non-uniformity.

The compositions optionally include additives selected from a groupconsisting of additives for removal rate selectivity, pH adjusters,conductivity adjustors, surfactants, dispersants, biological growthinhibitors, and combinations thereof.

Additives for Removal Rate Selectivity

Additives affecting removal rate selectivity include, but are notlimited to, additives having a functional group selected from the groupconsisting of organic carboxylic acids, amino acids, amidocarboxylicacids, N-acylamino acids, and their salts thereof; organic sulfonicacids and salts thereof; organic phosphonic acids and salts thereof;polymeric carboxylic acids and salts thereof; polymeric sulfonic acidsand salts thereof; polymeric phosphonic acids and salts thereof;arylamines, aminoalcohols, aliphatic amines, heterocyclic amines,hydroxamic acids, substituted phenols, sulfonamides, thiols, polyolshaving hydroxyl groups, and combinations thereof;

Chemical additives affecting removal rate selectivity include, but isnot limited to a compound having a functional group selected from thegroup consisting of organic carboxylic acids, amino acids,amidocarboxylic acids, N-acylamino acids, and their salts thereof;organic sulfonic acids and salts thereof; organic phosphonic acids andsalts thereof; polymeric carboxylic acids and salts thereof; polymericsulfonic acids and salts thereof; polymeric phosphonic acids and saltsthereof; arylamines, aminoalcohols, aliphatic amines, heterocyclicamines, hydroxamic acids, substituted phenols, sulfonamides, thiols,polyols having hydroxyl groups, and combinations thereof.

Preferred chemical additives affecting removal rate selectivity include,but are not limited to, polyacrylic acid or its derivatives; andpolyethylene glycol, polyol comprising hydroxyl groups such as sorbitol,galactose, arabinose, ribose, xylose, maltitol, lactose, maltose andmixtures thereof. Preferred molecular weight of polyacrylic acidcompound is between 500 and 100,000, or more preferably between 1,000and 50,000 and most preferably between 5,000 and 20,000. Polyethyleneglycol molecular weight can range from 1,000 to 20,000, and morepreferably between 5,000 and 15,000.

When present, the amount of chemical additive ranges from about 0.01weight percent to 2 weight percent relative to the total weight of theCMP composition. The preferred range is from about 0.05 weight percentto 1 weight percent and more preferred range is from about 0.1 weightpercent ppm to 0.5 weight percent.

pH Adjustors

The pH of the composition may be adjusted using an appropriate pHadjusting agent, such as a suitable acid, base, amine, or anycombination thereof. Preferably, a pH adjusting agent used in thecomposition does not contain metal ions, such that undesirable metalcomponents are not introduced into the composition.

Preferred agents for adjusting pH include, but are not limited to,sodium hydroxide, cesium hydroxide, potassium hydroxide, cesiumhydroxide, ammonium hydroxide, quaternary organic ammonium hydroxide(e.g. tetramethylammonium hydroxide), nitric acid, phosphoric acid,sulfuric acid, organic acids, and/or salts thereof, amines, and mixturesthereof.

When present, the amount of pH-adjusting agent ranges from about 0.0001to about 5 weight percent relative to the total weight of the CMPcomposition. The preferred range is from about 0.0005 to about 1 weightpercent, and the more preferred range is from about 0.0005 to about 0.5weight percent

Preferably, the pH of the CMP composition is greater than 5, morepreferably greater than 7.

Conductivity Adjustors

The CMP composition may contain additives to adjust the conductivity ofthe formulation. A preferred conductivity adjustor is potassium nitrate.

Surfactants

The CMP composition may comprise a surfactant or a mixture ofsurfactants. Surfactants may be anionic, cationic, nonionic orzwitterionic in nature. While there are many suitable surfactantadditives for the slurry, preferred surfactant additives include dodecylsulfate sodium salt, sodium lauryl sulfate, dodecyl sulfate ammoniumsalt, alcohol ethoxylates, acetylenic surfactant, polyethyleneimine,ethoxylated fatty amine and stearylbenzyldimethylammonium chloride ornitrate and any combination thereof. Suitable commercially availablesurfactants include TRITON DF 16™ manufactured by Dow Chemicals andvarious surfactants in SUIRFYNOL™, DYNOL™, Zetasperse™, Nonidet™, andTomadol™ surfactant families, manufactured by Evonik Industries.

Various anionic, cationic, nonionic and zwitterionic surfactants havingmolecular weight in the range from less than 1000 to greater than 30,000are contemplated as dispersants. Included are sodium, potassium, orpreferably ammonia salts of stearate, lauryl sulfate, alkylpolyphosphate, dodecyl benzene sulfonate, diisopropyl naphthalenesulfonate, dioctylsulfosuccinate, ethoxylated and sulfated laurylalcohol, and ethoxylated and sulfated alkyl phenol.

Various cationic surfactants include polyethyleneimine, ethoxylatedfatty amine and stearylbenzyldimethylammonium chloride or nitrate.

Addition of a surfactant may be useful to reduce thewithin-wafer-non-uniformity (WIWNU) of the wafers, thereby improving thesurface of the wafer and reducing wafer defects.

The CMP composition may comprise a dispersing additive to stabilizeparticle dispersion.

When present, the amount of surfactant ranges from about 0.0001 to about10 weight percent relative to the total weight of the CMP composition.The preferred range is from about 0.001 to about 1 weight percent, andmore preferred range is from about 0.005 to about 0.1 weight percent.

Dispersants

The suitable dispersing additive includes but is not limited to organicacids and their salts; polymeric acids and their salts; water solublecopolymers and their salts; copolymers and their salts containing atleast two different types of acid groups, such as carboxylic acidgroups, sulfonic acid groups, or phosphonic acid groups in the samemolecule of a copolymer, polyvinyl acid and salt thereof, polyethyleneoxide, polypropylene oxide, and combinations thereof. Some examples ofdispersants include: polyethylene glycols; lecithin; polyvinylpyrrolidone; polyoxyethylene; isoctylphenyl ether; polyoxyethylenenonylphenyl ether; amine salts of alkylaryl sulfonates; polyacrylicacid, polymethacrylic acid and their salts.

When present, the amount of dispersant ranges from about 0.0001 weightpercent to about 10 weight percent relative to the total weight of theCMP composition. The preferred range is from about 0.001 to about 1weight percent, and more preferred range is from about 0.005 weightpercent to about 0.1 weight percent.

Formulations may also comprise water soluble polymers which may compriseanionic or cationic or non-ionic or zwitterionic combinations of groups.

Biological Growth Inhibitors

CMP formulations may also comprise additives to control biologicalgrowth such as biocides. Some of the additives to control biologicalgrowth are disclosed in U.S. Pat. No. 5,230,833 (Romberger et al.) andUS Patent Application No. US 20020025762. Biological growth inhibitorsinclude but are not limited to tetramethylammonium chloride,tetraethylammonium chloride, tetrapropylammonium chloride,alkylbenzyldimethylammonium chloride, and alkylbenzyldimethylammoniumhydroxide, wherein the alkyl chain ranges from 1 to about 20 carbonatoms, sodium chlorite, sodium hypochlorite, isothiazolinone compoundssuch as methylisothiazolinone, methylchloroisothiazolinone andbenzisothiazolinone. Some of the commercially available preservativesinclude BIOBAN™ 425, KATHON™ and NEOLONE™ product families from DowChemicals and Preventol™ family from Lanxess.

The preferred biocides are isothiozilone compounds such asmethylisothiazolinone, methylchloroisothiazolinone andbenzisothiazolinone. The CMP polishing compositions optionally contain abiocide ranging from 0.0001 to 0.10 weight percent, preferably from0.0001 to 0.005 weight percent, and more preferably from 0.0002 to0.0025 weight percent to prevent bacterial and fungal growth duringstorage.

Methods of Use

In one exemplary embodiment, a system for chemical mechanicalplanarization comprises a patterned substrate comprising at least onesurface having a first material and a second material, a polishing pad;and the polishing composition described above. The at least one surfaceis in contact with the polishing pad and the polishing composition. Thefirst material is a silicon oxide material selected from the groupconsisting of thermal oxide, TEOS films deposited using Tetra EthylOrtho Silicate (TEOS) precursors, High Density Plasma (HDP) oxide, HighAspect Ratio Process (HARP) films, fluorinated oxide films, doped oxidefilms, Spin-On Glass (SOG), flowable Chemical Vapor Deposited (CVD)films, optical glass, display glass, and combinations thereof. As usedherein, doped oxide films include, but are not limited to, oxide filmsthat are fluorine doped, carbon doped, boron doped, phosphorus doped,nitrogen-doped or combinations of thereof.

In an exemplary embodiment, a polishing method for chemical mechanicalplanarization of a semiconductor device comprises at least one surfacehaving a first material and a second material. The method comprises thesteps of: contacting the at least one surface with a polishing pad;delivering the polishing composition described above to the at least onesurface, polishing the at least one surface with the polishingcomposition to remove the first material at a removal rate of greaterthan 10000 Angstroms/min., preferably greater than 12500 Angstroms/min.,more preferably greater than 15000 Angstroms/min.

The first material is a silicon oxide material selected from the groupconsisting of thermal oxide, TEOS films deposited using Tetra EthylOrtho Silicate (TEOS) precursors, High Density Plasma (HDP) oxide, HighAspect Ratio Process (HARP) films, fluorinated oxide films, doped oxidefilms, Spin-On Glass (SOG), flowable Chemical Vapor Deposited (CVD)films, optical glass, display glass, and combinations thereof.

Silicon oxide films may be generally referred to as oxide films in thedescription. Silicon oxide films could include variety of films andmaterials including but not limited to thermal oxide, films depositedusing Tetra Ethyl Ortho Silicate (TEOS) precursors, High Density Plasma(HDP) oxide, High Aspect Ratio Process (HARP) films, fluorinated oxidefilms, doped oxide films, Spin-On Glass (SOG), flowable Chemical VaporDeposited (CVD) films, optical glass, display glass. As used herein,doped oxide films include, but are not limited to, oxide films that arefluorine doped, carbon doped, boron doped, phosphorus doped,nitrogen-doped or combinations of thereof.

In some embodiments, the CMP formulations can be used in stop-in-filmapplications, where the polishing is stopped once the topography isremoved and a flat surface is achieved. In other embodiments, theseformulations can be used in applications that involve polishing the bulkfilm and stopping at a stopper layer. The stopping layer may comprise asilicon nitride or poly-Si film. Silicon nitride film may be representedby a general formula Si_(x)N_(y), where the ratio x/y may range from 0.1to 10. The silicon nitride may also incorporate other elements such asbut not limited to oxygen, carbon, nitrogen.

In preferred embodiments, the silicon oxide films are polished at a rategreater than 10000 Å/min, or more preferably more than 12000 Å/min ormost preferable greater than 15000 Å/min when the blanket films arepolished at 4 psi downforce and 126 RPM table speed with 150 ml/minslurry flow rate on a 300 mm wafer polisher. In some other embodimentsremoval rate selectivity between the oxide and the stopper film greaterthan 10, or more preferably greater than 30.

One skilled in the art will understand that the slurry can be used withregular or fixed abrasive pads, can be shipped as concentrate, can besingle or multi-component pack, and in case of multi-component pack, canbe used in in-situ or ex-situ mixing mode.

WORKING EXAMPLES

Parameters:

Å: angstrom(s)—a unit of length

BP: back pressure, in psi units

CMP: chemical mechanical planarization=chemical mechanical polishing

CS: carrier speed

DF: Down force: pressure applied during CMP, units psi

min: minute(s)

ml: milliliter(s)

mV: millivolt(s)

psi: pounds per square inch

PS: platen rotational speed or table-speed of polishing tool, in rpm(revolution(s) per minute)

SF: polishing composition flow, ml/min

Removal Rates and Selectivity

Removal Rate (RR)=(film thickness before polishing−film thickness afterpolishing)/polish time.

All percentages are weight percentages (weight percent) unless otherwiseindicated.

General Experimental Procedure

In the examples presented below, CMP experiments were run using theprocedures and experimental conditions given below. The 300 mm CMP toolthat was used in the examples is a Reflexion LK®, manufactured byApplied Materials, 3050 Boweres Avenue, Santa Clara, Calif., 95054.IC1010 pads, IK4250UH pads, and IK4131 UH pads from Dow Chemicals wereused for polishing. TEOS oxide films were made by Chemical VaporDeposition (CVD) using tetraethylorthosilicate as the precursor. HDPoxide films were made using a high-density plasma (HDP) technique.

All the 300 mm wafer polishing was performed at 4 psi downforce, 126 RPMtable speed, 125 RPM carrier speed, 150 ml/min slurry flow rate andusing 30% in-situ conditioning (3MA122 disk) with 6 lb force and 115 rpmspeed. All the 200 mm wafer polishing was performed on 200 mm Ebara toolwith IC1010 pad at 4 psi downforce, 100 RPM table speed, 107 RPM carrierspeed, 300 ml/min slurry flow rate and 17 s ex-situ conditioning (diskKinik PDE781-NC) at 4 psi and 20 RPM table speed after each polish.

TEOS film thickness was 15,000 Å or 40,000 Å. HDP film thickness was10,000 Å. Ceria coated silica particles used in the examples below wereprocured from JGC C&C Ltd (Kawasaki City, Japan). Mean particle size ofthese particles measured by Disc Centrifuge analysis method (DC24000 UHRfrom CPS Instruments) was 155 nm.

Slurry Conductivity was measured with a EUTECH Con 110. Zeta potentialwas measured using a Colloidal Dynamics Zeta Potential Probe. Ceriaparticle density and dielectric constant values were used as surrogatesfor the composite particle's parameters in the calculations. Therefore,the zeta potential numbers given in the examples are to be interpretedonly for relative comparison.

Example 1

The CMP compositions comprised ceria coated silica particles at 4 weightpercent concentration and benzene sulfonic acid at variousconcentrations. Table 1 summarizes the compositions and the removalrates for TEOS films. Formulations were pH adjusted using ammoniumhydroxide.

TABLE 1 Ceria Benzene Coated Sulfonic Electrical Silica AcidConductivity Zeta Formulation (weight (weight of Slurry TEOS potential #percent) percent) pH (mS/cm) Removal Rate (mV) 1 4 0 9.0 0.055 11516−59.62 2 4 0.5 7.5 3.3 16381 −42.99 3 4 1.5 7.5 9.1 15891 −24.56

It is evident that benzene sulfonic acid provides significant removalrate boost for TEOS films. Formulation 3 was found to unstable, leadingto settling of the particles. It is evident that a zeta potential of atleast −30 millivolts or more negative, preferably more than −35millivolts may be needed to achieve a stable slurry.

Example 2A

CMP compositions comprising ceria coated silica particles at 4 weightpercent concentration and 2 weight percent MOPS were formulated atdifferent pH using ammonium hydroxide as pH adjuster. Table 2Asummarizes the removal rates for TEOS films as a function of pH. Theresults show that pH greater than 6 or 7 may be more optimal forincreased removal rates.

TABLE 2A TEOS Removal Rate pH (Å/min) 5.5 11610 7.5 15390 9 14079

Example 2B

CMP compositions comprising ceria coated silica particles at 2 weightpercent concentration were formulated at different pH using ammoniumhydroxide as pH adjuster or potassium nitrate as conductivity adjuster.Table 2B summarizes the removal rates for TEOS films as a function ofpH, taken on the 200 mm tool. The results show that higher pH suitablefor high rate for the slurries. At the same pH, higher conductivity issuitable for higher TEOS removal rates.

TABLE 2B pH adjuster/conductivity Conductivity TEOS Removal Rate pHadjustor (mS/cm) (Å/min) 11 NH4OH only 0.308 13506 10 NH4OH only 0.0611545 9 None <0.05 7771 9 KNO3, NH4OH 1.5 15836 9 KNO3, NH4OH 7.0 17336

Example 3

CMP slurry compositions were prepared comprising ceria coated silicaparticles at 4 weight percent concentration and picolinic acid at 0.1weight percent. The compositions also comprised different concentrationsof MOPS additive. The pH of the slurry formulation was adjusted to 7.5using ammonium hydroxide as pH adjuster. The data was generated using a300 mm tool.

TABLE 3 Electrical MOPS Additive TEOS Removal Rate Conductivity ZetaPotential Concentration (Å/min) (mS/cm) (mV) 0.5 15933 1.448 −52.31 1.515730 4.18 −41.22 2 15390 5.72 −37.88 2.5 16305 6.66 −35.08

Table 3 summarizes the 300 mm TEOS removal rate data as a function ofMOPS concentration. It shows that high removal rates can be maintainedacross a wide range of additive concentration. In contrast, inexperiments with formulations containing no MOPS additive, the TEOSremoval rate is in the range of 11000-12000 Angstroms/minute.

Example 4

Slurries were prepared comprising 3% composite ceria abrasive (ceriacoated silica) at pH 9. NH4OH was used to adjust the pH of the slurries.Carboxylic acids, phosphonic and phosphinic acids were added to thecompositions according to Table 4 below, and the slurries were testedboost provided to the TEOS removal rate, as reported in Table 4. All thewafer polishing was performed on 200 mm Ebara tool.

TABLE 4 Electrical TEOS Removal Additive Level Conductivity RateAdditive Name (wt. %) (mS/cm) (Å/min) None 0 .052 11792 Phenylphosphonicacid 0.1 1.30 16268 Phenylphosphinic acid 0.2 1.25 17081 Benzoic acid0.15 1.23 17144 Benzoic acid 0.07 0.66 16556 Acetic acid 0.08 1.33 17368Malonic Acid 0.13 2.07 16824 Glutaric Acid 0.166 3.44 16336 Oxalic Acid0.113 1.29 15055

It is seen from Table 4, that the compared to the control sample, allthe additives increase the conductivity of the slurry and also increasethe oxide removal rate. Without being bound to a particular theory,slurry conductivity is an important parameter for increasing oxideremoval rate.

Example 5

A 4 percent by weight composite ceria (ceria coated silica) abrasiveformulation, with pH adjusted to 9, with varying levels of BSA ratebooster were prepared and tested for RR in a 300 mm tool. The sameceria-based slurries were also diluted down to solid content of 0.008weight percent for suitable absorption. A high-resolution UV/Visspectrophotometer, JASCO V-550, was used to measure the absorptionspectra of the filtrates in the 200-500 nm wavelength region. Thesubject ceria abrasive has two characteristic absorption peak 211 and311 nm which mean Ce3+ and Ce4+ absorption respectively. The peak areaof Ce 3+ was characterized after normalizing to the Ce4+ peak area(245-500 nm); and also after subtracting the background from theadditive alone. The results are summarized in Table 5. It is expectedthat formulations with a higher Ce3+ fraction will increase the TEOSremoval rate. When glycine (2-aminoethanoic acid) was used as theadditive, no oxide rate boost was seen and correspondingly, no increasewas seen in the Ce3+ peak area. Without being bound by any particulartheory, the additives of the invention are also expected to increase theCe3+ fraction of the abrasive, and therefore boost the TEOS removalrate.

TABLE 5 Level (weight Conductivity % Change in TEOS RR Additive %) pH(mS/cm) Ce3+/Ce4+ ratio (A/min) BSA 0.5 7.5 3.3 +2.58 16380 BSA 0.5 93.3 Not done 14604 Glycine 0.5 9 0.12 −0.78 10870

Example 6

A CMP Slurry was prepared having a pH of 9, 4 percent by weigh ofcomposite ceria (ceria coated silica) abrasive and 0.5 percent by weightof BSA additive were prepared. Table 6 summarizes the polish rate on a300 mm Reflexion LK tool for TEOS oxide and HARP (High Aspect RatioProcess) oxide films with two types of pads (IC1010 and IK4250 UH). Asseen from Table 6, the exact polish rate depends on the type of film,and also type of pad. High rates of greater 2.5 microns/min can beachieved.

TABLE 6 300 mm pad polish rate A/min IC1010 pad IK4250UH pad TEOS oxide16381 20854 HARP oxide 19125 25501

Example 7

A calcined ceria abrasive and composite ceria abrasive (ceria coatedsilica) were compared in slurries comprising 3 percent by weight ofabrasive. The properties of the slurries and corresponding 300 mm TEOSfilm RR values are listed in Table 7. The RR values were obtained usingtwo different pads at the same process conditions (3MA122 disk, baselinepolish recipe as given above for 300 mm wafers). The composite ceriaabrasive is clearly better for obtaining higher TEOS removal rates, evenat the same abrasive level.

TABLE 7 Properties (3% Calcined ceria Composite ceria abrasive slurry)abrasive slurry abrasive slurry pH 9.74 9.11 Conductivity (micro S/cm)72 49 Zeta Potential (mV) −74 −62 IC1010 Pad, Oxide RR 8185 10367(A/min) IK4131UH Pad, Oxide RR 10197 14306 (A/min)

The foregoing examples and description of the embodiments should betaken as illustrating, rather than as limiting the present invention asdefined by the claims. As will be readily appreciated, numerousvariations and combinations of the features set forth above can beutilized without departing from the present invention as set forth inthe claims. Such variations are intended to be included within the scopeof the following claims.

The invention claimed is:
 1. A chemical mechanical planarization (CMP)composition for polishing oxide material consisting essentially of: anabrasive selected from the group consisting of calcined ceria, colloidalceria, ceria coated silica particles, and combinations thereof; aremoval rate accelerator having a pyridine group, wherein the pyridinegroup has a structure of:

wherein R1, R2, R3, R4 and R5 are independently selected from the groupconsisting of hydrogen, a carboxylic acid, a carboxylic acid ester, anorganic sulfonic acid, an organic amine, an organic amide and a hydroxylgroup; and a solvent, and optionally at least one additive selected fromthe groups consisting of an additive for removal rate selectivityselected from the group consisting of sorbitol, galactose, arabinose,ribose, xylose, maltitol, lactose, maltose and combinations thereof; apH adjuster selected from the group consisting of sodium hydroxide;cesium hydroxide; potassium hydroxide; ammonium hydroxide; quaternaryorganic ammonium hydroxide; nitric acid; phosphoric acid; sulfuric acid;and combinations thereof; a surfactant selected from the groupconsisting of dodecyl sulfate sodium salt, dodecyl sulfate ammoniumsalt, alcohol ethoxylates, acetylenic surfactant,stearylbenzyldimethylammonium chloride or nitrate, and combinationthereof; a dispersant selected from the group consisting of lecithin;isoctylphenyl ether; amine salts of alkylaryl sulfonates; andcombinations thereof; and a biological growth inhibitor is selected fromthe group consisting of tetramethylammonium chloride; tetraethylammoniumchloride; tetrapropylammonium chloride; alkylbenzyldimethylammoniumchloride or alkylbenzyldimethylammonium hydroxide, wherein the alkylchain ranges from 1 to about 20 carbon atoms; sodium chlorite; sodiumhypochlorite; methylisothiazolinone; methylchloroisothiazolinone;benzisothiazolinone; and combinations thereof; wherein the compositionhas a pH greater than 7; and the abrasive comprises particles having azeta potential more negative than −25 millivolts.
 2. The CMP compositionof claim 1, wherein the abrasive comprises ceria coated silicaparticles, the ceria coated silica particles comprising an amorphoussilica core particle coated with crystalline ceria nanoparticles.
 3. TheCMP composition of claim 2, wherein the crystalline ceria nanoparticlescomprise a single crystal.
 4. The CMP composition of claim 2, wherein aweight ratio of the ceria nanoparticles to the amorphous silica coreparticle is 0.01 to 1.5.
 5. The CMP composition of claim 2, wherein theamorphous silica core particles comprise a diameter ranging from 20 to550 nanometers and the ceria nanoparticles comprise a diameter greaterthan 10 nanometers, wherein the diameter of the amorphous silica coreparticles is greater than the diameter of the ceria nanoparticles. 6.The CMP composition of claim 1, wherein the solvent is selected from thegroup consisting of water, a polar non-aqueous solvent, and a mixturethereof.
 7. The CMP composition of claim 6, wherein the non-aqueoussolvent is selected from the group consisting of alcohol, ether, ketoneand combinations thereof.
 8. The CMP composition of claim 1, wherein atleast one of R1, R2, R3, R4 and R5 is a carboxylic acid.
 9. The CMPcomposition of claim 1, wherein the removal rate accelerator ispyridine, or an organic acid having a pyridine group selected from thegroup consisting of: pyridine monocarboxylic acid; pyridine dicarboxylicacid; picolinic acid; nicotinic acid; isonicotinic acid; dipicolinicacid; 2,5-pyridinedicarboxylic acid; 3,5-pyridinedicarboxylic acid;2,3-pyridinedicarboxylic acid; and 3,4-pyridinedicarboxylic acid. 10.The CMP composition of claim 1, wherein a pH of the CMP compositionranges up to
 11. 11. The CMP composition of claim 1, wherein aconductivity of the CMP composition ranges from 0.3 to 9 millisiemensper centimeter.
 12. A polishing method for chemical mechanicalplanarization (CMP) of a semiconductor device comprising a firstmaterial and a second material, comprising the steps of: (a) contactingat least one surface of the first material with a CMP polishing pad; (b)delivering the CMP polishing composition of claim 1 to the at least onesurface; (c) polishing the at least one surface with the polishingcomposition to remove the first material at a removal rate of greaterthan 10000 Angstroms/minute.
 13. The polishing method of claim 12,wherein the first material is a silicon oxide material selected from thegroup consisting of thermal oxide, TEOS films deposited using TetraEthyl Ortho Silicate (TEOS) precursors, High Density Plasma (HDP) oxide,High Aspect Ratio Process (HARP) films, fluorinated oxide films, dopedoxide films, Spin-On Glass (SOG), flowable Chemical Vapor Deposited(CVD) films, optical glass, display glass, and combinations thereof. 14.The polishing method of claim 13, wherein the second material isselected from the group of silicon nitride, polysilicon, andcombinations thereof.
 15. A system for chemical mechanicalplanarization, comprising: (a) a patterned substrate comprising at leastone surface having a first material and a second material; (b) apolishing pad; and (c) the CMP polishing composition of claim 1, whereinthe at least one surface is in contact with the polishing pad and thepolishing composition and the first material is a silicon oxide materialselected from the group consisting of thermal oxide, TEOS filmsdeposited using Tetra Ethyl Ortho Silicate (TEOS) precursors, HighDensity Plasma (HDP) oxide, High Aspect Ratio Process (HARP) films,fluorinated oxide films, doped oxide films, Spin-On Glass (SOG),flowable Chemical Vapor Deposited (CVD) films, optical glass, displayglass, and combinations thereof.